Long time lurker, first time poster. Hello.

Little bit about me, I knew about PWM for a while affecting me. I got a 4k TV about 2 years ago that caused me lots of problems and had to return it. Had to return devices with PWM as well. Last year I wanted a smaller laptop, I got a 2015 13 Macbook pro 2nd hand, I'd had Macs before and they were fine. I cant use it, within minutes I get a crushing burning headache. It doesnt have PWM - you guys know this though, a lot of you are also affected in the same way. - and as you all know its not needing Flux its not needing to look away every 20 minutes.

I get migraines a lot, glasses perscription is correct. Bright light seems to affect me. IPS displays often seem too bright and may be a problem for me apart from my good laptop and phone. OLED is bad for me yet I had an S6 with OLED and PWM and it was fine until it broke.

I've got a laptop I got new in 2016/17 with an Intel I7 6th gen, HD520 and GTX 1060, 15 inch IPS screen. Its totally fine. Again same sort of year got an LG G6 phone has pwm below 38% (?) brightness at 2500 (ish) hz, is totally fine for me. Got a Lenovo T540 (2013?), HD4600 graphics TN screen, PWM below 40%, but fine for me above that. Lenovo Z500 (2012?) TN screen totally fine. Dell 5590 (2018) bad like the Mac.

I got another 2nd hand laptop as I cant use the Mac and wanted something a bit smaller than my i7 laptop, figured stick with the good and get HD520, got a Lenovo T460, HD520, same as my laptop thats good. I could use it for a day, then I updated it (big mistake) - now it burns and hurts like the Mac. Edit: I also tried Ditherig on it, made no difference to me, neither did disabling the hd520 in device manager.

What changed? - I cant get the same driver version. Intel site doesnt go that 'old' for me compared to my 'good' laptop. What else changed? - device manager 'Generic PnP monitor' with 2006 year default drivers, this changed to 'widescreen something something something display.....'

I've rolled this back to the default by uninstalling it, as soon as it changed back to Generic PnP display I could feel a difference in the way the screen affected me, but I already have a headache now so it may be a day or so before I Can test again.

Has anyone else had success rolling drivers back this way?

Edited a few times for detail....

I'm don't have much advice to offer, but I do have a question, When you turn ditherig.exe on on your T460 do you see a difference in picture quality? if its working you should see smooth colour gradients turn to bands - only on laptops though.

I can sort of recommend Vitamin B2 / Feverfew for migraines. They reduce the level of serotonin in your brain, which is required to initiate a migraine. Of course, serotonin is important for feeling alert and happy so its a trade off. When I am taking either it takes a lot more screen exposure to trigger a migraine and they hurt a lot less.

No real difference on the T460 with ditherig, the panel is not very good though, running though the calibration websites half of the example images dont display correctly due to the default / adjusted contrast / gamma etc. I did see some banding beforehand. I'm wondering if its a bad panel as its several years old and has some damage already. - If anything I may have made it worse messing with the color calibration in Windows. Hopfully when I try it again tomorrow its ok and I'll check some calibration sites for banding.

Didnt you test various machines / intel graphics for dithering and found the 6th gen ones dont actaully do it though?

Or reading it again if I've found the right one its was the 1060 that does, which is interesting because one of my 'good' laptops has a 1060 and its totally fine to use.

I already take a lot of things for the migraines, I also have a doctors appointment coming up where im going to yet again ask for some tests and hopefully not be ignored.

EDIT: couldnt wait. Tried the T460 again, there is banding using the lagom LCD calibration site. When I enable Ditherig there is much more banding and it makes my eyes feel funny looking at it. Pinching pressure sort of sensation.

Still cant tell if my headache is getting better / worse on it. But the ditherig on-off test did affect me.

Probably should stop looking at it for today. (a staggering productive 30 minutes total screen time, and I got this to do 'work' on!)

    HAL9000

    6th gen intel desktop chips are OK as far as I can tell. But they can dither, it can be turned on using Ditherig.exe

    I can't test laptop displays, but from my own experience ditherig.exe does seem to turn off the dithering, judging by the banding that appears. It sounds like this is the case for your laptop. Why is it causing you discomfort then? I'd guess it might be screen PWM. Your updates could have affected that, I have software for my thinkpad T410s to change to the PWM frequency, but I've no idea if it actually works.

    If you haven't got one, and you need a good computer, I'd recommend getting a normal intel desktop and a flicker free monitor. I personally have not found a single laptop that I can use without drugs to keep the migraines at bay.

    You'll find that most monitors use dithering as well, but I have had far greater success with them than laptops. Why? well I am again just guessing but I think it comes down to how the dithering is implemented. Desktop monitors will probably have a dedicated dithering chip that produces a kind of random static dithering field. Because its random, there are none/few patterns for our brains to pick up and stress over. GPU driven dithering can't do this though, as GPUs cannot produce random numbers efficiently. Instead GPUs probably apply some rigid mathematical algorithm, which I presume repeats fast enough to trip up our visual processing system. You've probably seen some of this on the Lagom site? they have some dithering example gifs if I remember correctly.

    My favoured monitor is the Benq BL2211, though you'll probably need to try a few different monitors before you get one that works for you. What works for you could well be down to the dithering method used.

      7 days later

      Its not PWM, all my screens are PWM free confirmed with various tests. Thats why I purchased them I was very sure to get PWM free screens.

      Its the same as the OSX issue, looking at a Macbook for a few moments starts a fire inside my head and it hurts for hours / days. Connecting to a GOOD external screen causes it to be BAD. My personal laptop and work t540 are fine on my external screens for hours, the T460 or macbook pro 2013 13' on the same external screens cause the same symptoms - even though the T460 and my personal laptop have the intel HD520.

      PWM is a different sensation to me, it hurts my eyes whereas this 'issue' is like a burning pain in the middle of my head that can radiate towards the top, then sometimes it feels like a tight band around my head sort of pressure / crushing pain and I feel sort of sick and diorentated.

      Due to the coronavirus my recent doctors appointment was via phone and he was not impressed by everything that I tried to explain, he said its just migraines and that I should stop looking at trigger items. So basically I'm going to work in IT but not be able to use computers. Going to suggest I start on some medication - at this point I'm willing to try anything even though in the past it hasnt helped. Going to ask to see a more qualified eye doctor as well to try and rule out convergence issues etc. - I'm already doing eye 'exercises' but so far no help.

      Anyway I rolled the T460 back to 2017 in the BIOS, thats as far back as I can take it. Rolled back Windows drivers as well but also still bad. Might format and re-do windows.

      Also same on Ubuntu on the T460 - as is my macbook. Tried that with W10, Ubuntu 19 and elementaryOS. Causes the same issue.

      Other than that I am also fully willing to go insane and just buy loads of machines to try and hopefully be able to return them if they're bad....ebay here I come I guess....

      The ONE thing thats possibly an issue is the screen on the T460 is damaged already, it has pressure marks where its much brighter so i cover that bit with a small piece of tape....I'm wondering if the damage is partially a problem so looking at a replacement screen.

      ALSO, my 2018 iPad is totally fine for me, but If i turn 'reduce white point' OFF it gives me similar symptoms.

      I previously had similar but not as pronounced symptoms when using android devices with 'eye care / comfort view' (warming the screen color temp) set to OFF but I managed to condition myself to it on the LG L6 (again brightness above the PWM level at all times on this) - I only have comfort view set at night rather than all the time so I'm trying that on the ipad.

      Its almost like on IPS screens colors are too 'bright' regardless of brightness settings and using software to dull colors doesnt work, however reduce white point on IOS DOES help.

        HAL9000 Its almost like on IPS screens colors are too 'bright' regardless of brightness settings and using software to dull colors doesnt work, however reduce white point on IOS DOES help.

        If dithering is enabled on a machine it might have this sort of saturated look to it. Comparing W10 white to W7, W10 is very clinical and harsh but W7 is an almost 'milky' white. However we don't know if it's drivers causing this or the OS itself...

        You also need to have a bonafide strain free piece of tech to use in testing these new monitors. I was sceptical that I would get on with the Dell U2419H (Despite owning a U2414H for several years). I bought it at the same time as a new computer, and was starting to think the monitor was the issue, but lo and behold, plugging my old gear into the new monitor got rid of any negative symptoms (at least in my experience).

        HAL9000 Other than that I am also fully willing to go insane and just buy loads of machines to try and hopefully be able to return them if they're bad....ebay here I come I guess....

        I'm a few years ahead of you in this regard. I have probably bought and tested over 20 machines in the last 5 years. Unfortunately anything from eBay will probably have the latest BIOS flashed and could be a cause of strain. Out of all the machines I've tried only one machine was good, but its pre-2010 (Acer Aspire M3802: I bought the same model new in 2010 but upgraded to a Mac Mini in 2014 and sold it). All I can recommend is an Intel desktop (Clarkdale gen and previous). As for Laptops.. I have had good experiences with HD4000 laptops and a Toshiba Satellite (AMD) desktop from early 2010's. Oh and also, W10 isn't a viable option either. W7, an old (2010 and previous) desktop/laptop, ensuring the BIOS is as close to build date as possible, and the original display drivers for the machine should work well.

            Yeah I've got 3 good machines that work fine with these monitors, the most surprising thing to me is the HD520 in the T460 seems to be bad yet the HD520 in my personal laptop is fine...

            Uhhhhhhh, so while I write this it seems that even though the T460 and my personal laptop are Skylake intel 6th gen, my laptop has a HD530 but the T460 has a HD520. 😅 well this may have been an expensive mistake....guess I'll look for something with a HD530 and learn to read properly.

              6 days later

              Before you give up on your laptop, try this driver version. My work T480 uses an Intel 620 GPU and the driver version in it is 12/27/2017 23.20.16.4905 and it seems to be usable on this particular hardware especially with the displayport to displayport or displayport to dvi output.

                ravipra the T460 has an i5 6300u and a HD520, my other laptop has a i7 6700hq and a HD530 and I just didnt realise as I thought all skylake had HD520.

                Otherwise after this is all over I'm going to look for something with a HD4600 like the T540 which is fine. Maybe also a new screen for the T460.

                Sunspark - I'll try and get that for the DELL machine I have with a HD620 and see if it helps

                      Sunspark I cant seem to find drivers that old on the intel site

                      Might have found it on the DELL site, giving it a go!

                      OK! found it....27/12/2018 23.20.16.4905 Dell download page for a 3300 someting 2-in-1. Also gave me the option to pick from HD510 onwards when installing via 'have disk' so maybe I can get this on the T460.

                      The problem? Using the Dell has given me a headache almost immediately even on 100% brightness to get around the PWM - so not sure if this will help. Might give it a couple days and try again / do it on the T460 as well and selecf HD520.

                          HAL9000 Here, this is for Lenovo. http://download.windowsupdate.com/c/msdownload/update/driver/drvs/2018/01/9cf30af6-b850-4107-9db8-7e70294ae286_4fec8af4a95ece392cf19fb611c6e3ffa45a8397.cab

                          You're probably unfamiliar with installing from a cab file, it's not too hard. Use your unzip or unrar program to extract the cab file to a folder. Then in device manager select the card, update driver, browse my computer and navigate to the folder you extracted to.

                              HAL9000, If possible, please prefer a machine with i7 and fast RAM. Slower memory has a lot to do with eye strain. Since i7 typically has more cache than lower variants such as i5 it would also help.

                                  Sunspark Thats pretty much what I did for the driver I found on the Dell site. I'll try the machine out later today as my headache has subsided somewhat today. Can always try the one you linked but It'll probably be the same, the Dell one I found was just a bundled download for another machine that has the same hardware - although again it gave me the choice to select what adapter I had when installing.

                                  ravipra I would agree that i7 machines are normally 'better' but I dont think this has anything to do with RAM speed, unless its integrated graphics RAM speed. - however my work t540 has an Intel i5 4210m with Intel HD4600 graphics and DDR3 1600mhz (guessing) RAM and is totally fine on its 720p TN screen and my external IPS ultrawide and TN FHD screens.

                                  The DELL 5590 has a UHD620 and I'm guessing DDR4 2133 / 2400mhz RAM and is bad.

                                  Macbook Pro 2015 has 1866mhz DDR3 and is BAD on its intel iris whatever graphics. (in OSX / Windows 10 and several Linux installations on built in retina screen at all scaling settings and external screens also bad)

                                  T460 has an intel i5 6300u and 12GB of DDR4, however 4GB are integrated. I could try removing the 8gb module after the new driver test as I dont know what speed its running at. Probably 2133mhz.

                                  My personal i7 machine has 2133mhz DDR4 with HD530 and is fine, but it also has a GTX1060 with 6gb DDR5(?) but this isnt in use all the time.

                                  I've also got an older Lenovo with a 3rd gen i7 with 6GB 1000/1600mhz(?) DDR3 RAM and a GTX620 2GB and this is fine on its 720p TN screen and my externals, although I hardly use it as its got hardware problems.

                                  I've also got access to an older AMD laptop that is practically a potato with a screen attached, this is very low powered and is totally fine for the few times I've used it before giving up because its so slow - no idea on the full specs but its about 5 years old and has 4GB ram and a quad core cpu.

                                  However all my slower stuff is older and I think everyone agrees that monitor 'tech' changed around 2010-2015ish when people started getting eyestrain / headache problems even with flicker free screens.

                                  But still you may be on to something as dedicated graphics memory is usually always faster than RAM and my machines with dedicated graphics memory (faster) are ok for me, but older. I'll have to dig out the full specs.

                                        5 days later

                                        HAL9000, Right. The hybrid/switchable graphics cards are another story, though. My point about faster memory and more powerful cpus is that: Typically memory bandwidth is a scare resource on a machine and both CPU and display controller compete for this resource. For higher end CPUs (i7) there is more cache, so their frequency of going to the main memory is lesser than the lower end CPUs (i3). Similarly, given everything else the same, faster memory should help with giving a better display.

                                          12 days later

                                          Purchased a new screen for the T460 as I noticed some symptoms even before loading into windows, also did a fresh install of Windows after removing Linux...

                                          I think they've sent me a screen that only displays 262k colours (6bit?) so I would imagine it is heavily dithering going on.

                                          According to panelook the old screen was also 6bit but it also had pressure damage / bright white marks on.

                                          Ditherig only makes banding appear 'more' but maybe I'll try it on this setup.

                                          I was trying to purchase an AOU screen listed as 16.2M (8 bit?) not another innolux but its a bit of a lottery as to what you get. I was hoping not to get this one as I've not only read it has PWM at 25000hz but the 6bit.

                                          🙁 yeah this one is the same as the other. I'm starting to feel pressure in my head and my eyes are feeling very strained, maybe its the PWM and dithering (although one site said it has pwm but also that I could pay them for a color profile that would remove pwm, so maybe thats a scam)

                                          https://laptopmedia.com/screen/innolux-n140hca-eac/

                                          To be honest I'd gladly pay again to fix the issue but I Think the above is a scam, you cant remove pwm with a display profile.

                                          Guess I'll return this screen and try to get the AOU one.

                                          What I got:
                                          http://www.panelook.com/N140HCA-EAC_Innolux_14_LCM_overview_30958.html

                                          What I ordered:
                                          http://www.panelook.com/B140HAN01.3_AUO_14.0_LCM_overview_23640.html

                                          • JTL replied to this.

                                            HAL9000 (although one site said it has pwm but also that I could pay them for a color profile that would remove pwm, so maybe thats a scam)

                                            It's not a scam per se, I think it's just a glorified version of f.lux et al

                                                JTL I literally just put Flux on it and lowered it to 5500k but I think the 'damage' for today is done and I can feel it in my eyes / head already. Maybe I can come back to it tomorrow and try again before condeming it.

                                                So anyone know for sure is 262k 6 bit but 16.2m 8 bit, or is 16.7 8 bit? Every time I google this I get something different.

                                                  So it turns out I can put the 'bad' panels in my 'good' laptop as they're all 30 pin....so I've done that. Clearly theres a size difference but its on and working.

                                                  My good screen: http://www.panelook.com/LP156WF6-SPB1_LG%20Display_15.6_LCM_overview_24180.html

                                                  I think Its the panel for me, but I already had a headache. I'll swap them around over the next couple days and report back. Certainly feels a bit strained now looking at it. Maybe these 14 panels have very very high PWM???

                                                  dev